"EFSA recommends that women of childbearing age...select fish from a wide range of species, without giving undue preference to large predatory fish such as swordfish and tuna," it said in a statement.

"Above safe levels of intake, methylmercury is particularly toxic to the nervous system and developing brain," added Josef Schlatter, chair of the EFSA scientific panel on contaminants in the food chain.

"Exposure during pregnancy and early infancy is therefore of particular concern."

EFSA said further dietary studies should be carried out among vulnerable population groups, including children and women of child-bearing age, as specific intake data were lacking.